Efeitos da meliponicultura na diversidade genética de Melipona quadrifasciata 1836 (Apidae, Meliponini) na região sul do Brasil

Abstract

Social stingless bees have been manipulated by man since the pre-European civilization era; management practices include artificial colony division/multiplication and nest transport. We evaluated the effects of common management practices on the genetic diversity of Melipona quadrifasciata within its native range in southern Brazil. The proposed research hypotheses are: 1) Genetic diversity in meliponaries reflects natural variation and population genetic structuring; 2) Migrant nests can be identified; 3) Meliponaries in which colonies are artificially divided suffer from inbreeding. We employed microsatellite and mitochondrial DNA markers to test these hypotheses. The genetic diversity in our sample was compatible with that of feral populations investigated by other researchers, although this diversity was heterogeneously distributed. We observed that meliponaries subjected to intensive colony multiplication exhibited signs of inbreeding. We also found haplotypes of various origins in meliponaries into which colonies had been introduced, which affected local diversity and resulted in the homogenization of allele frequencies in various regions. Although no genetic structuring was observed, a clinal genetic differentiation was found based on microsatellite markers. The mtDNA analyses showed geographic displacement of the queens, in addition to the introduction of haplotypes from the southeastern region of the country. Population differentiation and isolation by distance could not be used to effectively delimit management units based on natural gene flow. We suggest that efforts to preserve genetic diversity should focus on regulating management practices, allowing gene flow only via natural vegetation fragments, and that diversity management should focus on local regions, reflecting geographic and sociopolitical scenarios already utilized in other environmentally oriented natural population management plans.